<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
<script type="text/javascript" src="../js/jquery.js"></script>
<script type="text/javascript">
	$(function(){
		$('ul li:eq(2)').click(function(){
			$(this).css('font-size','30px')	;
		});
		
		$('#b1').click(function(){
			var $obj = $('ul li:eq(2)').clone();
			$('ul').append($obj);
		});
	});
</script>
</head>
<body>
	<ul>
		<li>item1</li>
		<li>item2</li>
		<li>item3</li>
	</ul>
	<input type="button" value="点击" id="b1"/>
</body>
</html>